Over time, the diaphragm valve of ventilation of crankcase gases and drying tears.
Torn through the membrane into the engine misses unaccounted mass air flow sensor.
As a result, the engine can be difficult to start, unstable work (especially at idle) may be misfiring, as the engine can get dust, which contributes to the deterioration of parts and mechanisms.
If the whistle is heard in the area of ​​finding the separator, then the membrane is torn.